The present invention relates to the use of impact modifying agents in smoking articles which articles preferably produce an aerosol that resembles tobacco smoke and which preferably contain no more than a minimal amount of incomplete combustion or pyrolysis products. More specifically, the invention relates to impact modifying agents for inclusion in the aerosol generating means of such smoking articles in order to improve the palatability of the aerosol produced during smoking by modulating the impact of the aerosol, e.g. by controlling the degree of harshness perceived by the user as irritation and impact in the mouth, nose and throat of the user.
Cigarette-like smoking articles have been proposed for many years, especially during the last 20 to 30 years. See for example, U.S. Pat. No., 4,079,742 to Rainer et al; U.S. Pat. No. 4,284,089 to Ray; U.S. Pat. No. 2,907,686 to Siegel; U.S. Pat. Nos. 3,258,015 and 3,356,094 to Ellis et al.; U.S. Pat. No. 3,516,417 to Moses; U.S. Pat. Nos. 3,943,941 and 4,044,777 to Boyd et al.; U.S. Pat. No. 4,286,604 to Ehretsmann et al.; U.S. Pat. No. 4,326,544 to Hardwick et al.; U.S. Pat. No. 4,340,072 to Bolt et al.; U.S. Pat. No. 4,391,285 to Burnett; U.S. Pat. No. 4,474,191 to Steiner; and European Patent Appln. No. 117,355 (Hearn).
As far as the present inventors are aware, none of the foregoing smoking articles or tobacco substitutes have ever realized any commercial success and none have ever been widely marketed. The absence of such smoking articles from the marketplace is believed to be due to a variety of reasons, including insufficient aerosol generation, both initially and over the life of the product, poor taste, off-taste due to thermal degradation of the smoke former and/or flavor agents, the presence of substantial pyrolysis products and sidestream smoke, and unsightly appearance.
Thus, despite decades of interest and effort, there is still no smoking article on the market which provides the benefits and advantages associated with conventional cigarette smoking, without delivering considerable quantities of incomplete combustion and pyrolysis products.
In late 1985, a series of foreign patents were granted or registered disclosing novel smoking articles capable of providing the benefits and advantages associated with conventional cigarette smoking, without delivering appreciable quantities of incomplete combustion or pyrolysis products. The earliest of these patents was Liberian Patent No. 13985/3890, issued 13 Sep. 1985. This patent corresponds to a later published European Patent Application, Publication No. 174,645, published 19 Mar. 1986.
In an effort to improve the palatability of the aerosol produced by smoking articles of the type described in the foregoing foreign patents, numerous additives including many of those described in Gibson et al., U.S. Pat. No. 3,878,850 were evaluated. Virtually all of these additive materials suffered from one or more disadvantages. For instance, many of these additives, particularly the low molecular weight additives, tended to evaporate or migrate away from the smoking article. Such additives were ineffective in reducing the harshness of the aerosol produced, particularly if any shelf life is required of the smoking article. Many other additives had an unpleasant taste or odor.